Northern Ireland’s attorney general has recommended a new inquest into a bombing by loyalist paramilitaries that killed 15 people, including two children, in Belfast in 1971. Brenda King decided the massacre at the Catholic-owned McGurk’s bar, in north Belfast, merited fresh scrutiny amid new evidence about the location of army observation posts near the atrocity. Survivors and campaigners have long believed there was state collusion in the attack by the Ulster Volunteer Force. The decision, disclosed on Friday, came just before the Northern Ireland Troubles (Legacy and Reconciliation) Act comes into force on 1 May. The controversial legislation will halt all Troubles-related inquests that are not at a ruling stage. Lawyers for relatives of two of the victims, Edward Keenan, 69, and his wife, Sarah Keenan, 58, said they were advised the attorney general had recommended a fresh inquest. Gerard Keenan, who was 13 when his parents were killed, said he welcomed the decision. “All the families have campaigned with great dignity for over 52 years for scraps of truth and justice from the British state,” he said in a statement. “Like many other bereaved families now, though, we face the reality that the British state will not allow this inquest to go ahead as it desperately wants to stop us from discovering why our loved ones were murdered in the McGurk’s bar massacre and how it failed to prevent it.” After the attack on 4 December 1971, authorities blamed the IRA and suggested the bomb exploded prematurely while being handled in the pub. It was later established to be the work of the UVF. One man was convicted of all 15 murders in 1978. Campaigners found army logs that identified military observation post locations that appeared to contradict army claims that there were no units in the area at the time of the attack. “Investigation of the actions or inactions of the army in the period before the bombing occurred is incomplete,” said a letter from the attorney general to campaigners, which was shared with the BBC. “The attorney considers that an inquest would provide a forum in which the actions of the army prior to the bombing could be explored.” Niall Ó’Murchú, a solicitor who represents the Keenan family, said the legacy act would thwart a new inquest but that legal challenges to the legislation left its fate unclear. The police ombudsman in 2011 rejected claims of collusion between the UVF and the Royal Ulster Constabulary but concluded there was investigative bias towards blaming republicans.